About your first slipup; how is it a slipup that Beedrill says its Japanese name? Pokemon do not necessarily have to say their name. I don't think I've ever heard Beedrill say its name; otherwise they would have to rename Staryu "Hey-ya", and Victrebell "Ahhhhh!!!". Maybe that name Beedrill said is what Beedrill is supposed to say, in the translated version that is.
While the second one is a real mistake, the beedrill thing is not. Not all Pokemon say their names, Beedrill for one just buzzes venomously (refer to the episode where Ash's Metapod evolves.)
The first comment about Victreebell saying 'aaahhhh'; I don't know if it's a slipup or not, but in the first episode where James got Victreebell (The Breeding Center Secret), they are in the jail and Victreebell clomps on to James for the first time. When it does so it says 'tree bell' in a deep voice.
Ok, first off, as an "expert" in this field, I'd like to say that Staryu does not say "Hey-ya" he/she/it actually says "Star-ya" only the "star" sounds more like "stay". Also, Victreebell was originally scripted to say "VicreeeeeeeeBell"(See "The Breeding Center Secret") But to save time (and sanity), was later changed to a simple "Vicreeee" (The Vic is very hard to hear, but listen closely, it is there.)
Hope this helps,
P1kachu534 (No, it's not my real name. Duh...!)
One of the many Pokémon dubbers at 4Kids entertainment.
(Hey, it pays good) ;)